Pass Labs XP32 or XP22?

Go to the source, no one knows more.  I would call or email Pass Labs and discuss with them.  There's a guy that just does the preamp design and guessing you can dialog with him.  I believe it is Wayne Colburn.  Let them know exactly what you are trying to accomplish, what equipment you have and your room size.  When it is good, it is really, really good.  I I don't think they will just try to up-sell and you can tell if that is their goal pretty quickly.  Sometimes creators are just geeking out on their own thoughts and circuitry but ask pointed questions about "sound quality".  Engineers can be fun.  You can also ask about other speaker suggestions and things. 

Look elsewhere. Pass amplification is fantastic...their preamps are anemic and not terribly musical, in my experience. I paired my XA60.8's first with an XP20, then an XP30, and was let down considerably with each "step up". I worked with Aric at Aric Audio on a bespoke tube preamp and those Pass amps sang like never before. 

I have long paired a Audio Research preamps with Pass Labs amps. This is a very good combination to get the most out of great Pass amps.